Axel teodor nygren



(No Model.)

A. T. NYGREN. PORTABLE SGAPFOLD 2 SheetsSheet 1.

INVE NTORI e/ m xl (No Model.) 2 Sheets-Sheet 2.

A. T. NYGREN.

- PORTABLE SOAFFOLD.

No. 447,898. Q Patented Mar. 10,1891.

\ INVENTOR:

W TNESSES: 5

Attorney.

-UNITED STATES.

ATENT Orrrcn.

AXEL TEODOR NYGREN, OF STOOKHOLM, SWEDEN, ASSIGNOR TO ANDERS VICTOR CARLSON AND PETTER JOHAN ALFRED NYGREN, OF SAME PORTABLE SCAFFOLD.

SPECIFICATION forming part of Letters Patent No. 447,898, dated March 10, 1891.

Application filed November 19, 1889. Serial No. 330,934- (No model.) Patented in Sweden August 8, 1889, No. 1,928, and in Germany September 20, 1889, No. 48,608.

T0 on whom it may concern:

Be it known that I, AXEL TEODOR NYGREN, a subject of the King of Sweden, residing at Stockholm, Sweden, have invented certain Improvements in Portable Scaffolds, (for which a patent has been granted in Sweden, No. 1,928, dated August 8, 1889, and in Germany, No. 48,608, dated September 20, 1889,) of which the following is a specification.

a? My invention relates to a scaffold for exterior work on buildings, which may be moved sidewise orlaterally, so that the workman may by means thereof be able to transfer himself from one part of the face of the building to another as the work progresses. This scaffold forms a substitute for a stationary scaffold such as is usually employed for such work.

In the accompanying drawings, illustrative of my invention, Figure l is a perspective View of a scaffold embodying my improvements mounted on a building. Figs. 1'" and 1 are detail views, on a larger scale, of parts of the winding mechanism on the chair, the former being a side View of same and thelatter an end View. Fig. 2 is a detail View that will be hereinafter described. Fig. 3 is a side view of the bracket, showing its adaptation to a double-track rail for the carriage from which the chair is suspended.

The scaffold consists, substantially as shown in Fig. 1, of a hoisting-chair A, the bearingropes of which run on four pulleys B, fixed to a laterally-moving carriage, which, by means of two track-wheels 0, runs upon a rail D. The rail D extends along the whole front of the building and is supported by brackets fixed to the building in such a manner that its upper edge is free along the whole length, so that the hoisting-chair may be movedlaterally as far as the length of the rail. These brackets, of which only one is shown in the drawings, are so placed as to be fastened to the roof. The bracket comprises a bar a, secured adj ustably at its upper end to a support I), secured to the roof Y, and near the eaves to a support 0, which also rests on the roof. This bar to projects out over the cornice X of the house, where s it is connected adj ustably to a bar a, which projects inward obliquely toward the house-wall. A tie-bar a connects the bars a and a together adjustably, the three bars forming a triangular truss or frame. A bent or angular suspender a is coupled at its upper end to the free end of the bar a, and has a stirrup a at its lower extremity to receive the rail D. A brace a connects the suspender o to the projecting extremity of the bar a. The connected bars forming the, bracket are coupled together adjustably in order that the suspender a may hang vertically, whatever may be the angle of the roof, and this adj ust ability is attained by rows of holes in the respective bars and pinsd, to couple the bars together, through the medium of said holes, as clearly shown.

WVhere the track-rail D is necessarily long, it may be made in sections and these sections be secured together by fastenings at the points where said rail rests in the stirrups a of the brackets.

The suspended chair is provided with a tackle or purchase, so that it may be moved vertically and sidewise, either simultaneously or otherwise. With the crank-shaft K both the shafts Z are geared by means of bevel-wheels. On each of these shafts Z are two drums m for the hoisting-ropes m, and two other ropedrums n and 0, which, geared with the shafts Z, serve to move the suspended chair laterally. On the latter rope-drums ropes q are wound, the ends whereof are secured to the respective ends of the rail D and supported or guided on guide-sheaves p. The proportion of the gearing between the rope-drums n and 0 and the drums m m on shafts Z is such that when the suspended chair is raised or lowered by turning the shaft K the rope q will be taken up or let out from the drums at and 0 to the proper extent. If the pinion r on shaft Z be disconnected or disengaged, then the chair may be moved laterally by turning the respective drums at and 0, so as tounwind one rope g from one drum and wind the other rope g on the other drum. If both the drums at and o be loose and one of them be connected by means of the pinion r and the shaft K be turned, the chair A will at the same time be moved laterally and raised or lowered. Two ratchet-wheels s, with pawls or detents t, prevent the chair from falling, and two fenders it, provided with anti-friction rollers or the like at their ends, may, with the rollers, be pushed against the wall, so that the chair may not touch the wall, but will nevertheless be suspended firmly.

The shaft K may in lieu of a crank be provided with a wheel for turning it, or it may be rotated by means of screw-gearing. V here the building has a rounded corner, the rail D may be carried round this corner. At the gables the rail must be supported by ropes fixed to suspenders similar to suspender a provided with a bent piece, so that the suspender-arins shall stand projecting out from.

the wall, and at the top be fixed to beams passed through apertures in the gable or placed upon the roof, with the ends passing beyond the wall and fixed in a convenient manner to the roof.

Fig. 2 shows an arrangement for adjusting the chair sidewise horizontally while sus pended. This is etfected by winding up the slack of the rope left after raising or lowering-the chair. This device consists of a hookpawl c, engaging a ratchet-wheel d, fixed on the shaft Z, on which the rope-drums turn loosely. The hook-pawl c prevents the drum from turning round because of the strain on the rope. At the opposite end of the ropedrum there is a boss or center j, which has the form of a polygonal nut. If the rope is too long, the drum is turned a little by means of a wrench on this bass, so as to take up the slack or surplus. The hook-pawl has a spring to. keep it in engagement, and said pawl prevents the drum from rotating backward. It is evident that the drums at and 0, provided with the above-described device, may likewise be mounted directly on the respective shafts Z. Then it is desired to move the chair laterally, the drums will be turned by the aforesaid wrench and afterward locked by some suitable device. However, the wrench would preferably be fixed to the shaft as a crank, so that it could be used as a lever.

Fig. 3 shows how the carriage which supports the chair A may be mounted on two rails D instead of one, as seen in Fig. 1. This modification will require no special description. It is only necessary to modify the form of the suspender a, so that it has two stirrups instead of one to support the respective rails. I do not limit myselfto the specific details of construction of the chair, as the construction shown may be modified somewhat withoutmaterially departing from the principles of my invention.

Having thus described elaim 1. In a portable scaffold, the combination, with the rail or rails for supporting the carriage, of a bracket consisting of the bar a, which is supported on the roof and pro ects therefrom, the bar a, pivotally connected to the bar a, the tie-bar a connected adj ustably to the bars a and a, the three bars forming a triangle, the suspender for the rail or ra ls, and the brace a connecting the bar Ct with said suspender, substantially as set forth 2. In a portable scaffold, the combination, with the rail D and the carriage mounted thereon and provided with supporting-pulleys and guide-pulleys, of the chair A, the rope-drums m m and their shafts mounted on said chair, the hoisting-ropes on said drums, which pass over the respective supportingpulleys on the carriage, the rope-dru ms n and 0 on the chair, geared to the shafts of the drums m, the ropes g on said drums, which pass over the respective guide-pulleys on the carriage and are secured to the respective ends of the rail D, and the crank-shaft K, geared at its ends to the respective shafts lot the drums on, whereby all the drums are or may be rotated simultaneously, for the purpose specified. I f 3. In a portable scaffold, the combination, with a support therefor, of the chair A, the four hoisting-rope drums m, mounted rotamy invention, I

tively thereon, two at each end thereof, as described, the shafts of said drums, the hoisting-ropes adapted to be wound on said drums when the chair is hoisted, and the longitudinally-arranged crank-shaft K on said chair, said crank-shaft being geared at its ends with the transverse drum-shafts, substantially as set forth.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

AXEL TEODOR NYGREN. Witnesses:

NERE A. ELFWING, ERNST SvAN visr. 

